1. Field of the Invention
The invention concerns personal care compositions formulated to impart moisturization and having excellent skinfeel properties.
2. The Related Art
Dry skin is a problem in varying degree to most humans. This condition is particularly evident in winter. Personal care products such as skin creams/lotions, shampoos/conditioners, toilet bars/shower gels and antiperspirants/deodorants are normally formulated with at least one material to address dry skin. Symptoms such as itching, flaking and a visually displeasing dermal appearance can all to some extent be modulated.
There are three traditional classes of materials employed against the problem. Occlusives such as petrolatum or silicone oils serve to inhibit loss of natural moisture. They form a barrier between the epidermis and the environment. Another approach is the use of keratolytic agents to enhance rate of dermal exfoliation. Alpha-hydroxy acids are the most common agents for achieving exfoliation.
A third approach to dry skin is topical application of humectants. Hydroxylated monomeric and polymeric organic substances are generally used for this purpose. Glycerin known also as glycerol is one of the most effective humectants.
Quaternary ammonium compounds have recently been commercialized as moisturizers. One of these known under the trademark Honeyquat 50 with INCI name of Hydroxypropyltrimonium Honey has been reported to be a better humectant than glycerin at levels of 2%. See the Arch/Brooks brochure titled “Cosmetic Ingredients & Ideas®”, Issue No. 2, August 2001. Honeyquat 50 is described as being derived from the reaction of pendent hydroxyl groups (on the disaccharide) of a “light” deodorized grade of honey with a chlorohydroxytrimethylammonium derivative. Another commercial quaternary ammonium moisturizer is Cola™ Moist 200 with INCI name of Hydroxypropyl Bis-Hydroxyethyldimonium Chloride. See the Colonial Chemical Inc. brochure titled “Cola™ Moist 200”, copyright 2004. U.S. Pat. No. 6,869,977 B1 (O'Lenick, Jr. et al.) to Colonial Chemical Inc. discloses a related monocationic material described as a moisturizing agent.
In there, the U.S. Pat. No. 7,659,233 B2 (Hurley et al.) discloses a composition that combines silicones with dihydroxypropyl trialkyl ammonium salts to deliver improved skinfeel properties. Although a significant advance, there is room for an improvement over this technology.
Many moisturizing actives impart to their formulas an aesthetically displeasing tack and/or sticky skinfeel. The present invention sought to provide a silicone containing moisturizing personal care composition having consumer pleasing skinfeel properties.